关于语法问题,新概念三册第一课puma at large

given by people这个过去分词短语作定语，修饰 the description ，而the description 是 were extraordinrily similar.、的主语。who claimed to have seen the puma 是一个定语从句用来修饰people的。过去分词做定语有表示被动的意思。
t整个句子：the description （描述）given by people(被人们给出的) who claimed to have seen the puma（宣称有看到过美洲狮的） were extraordinrily similar（极其相似).
那些宣称有看到过美洲狮的人给出的描述极其的相似。

give 过去式是 gave. given 是过去分词。
for the description given by people (人们给出的描述) were extraordinarily similar (都极其相似)。
过去分词一般用于‘完成时态和被动语态’。‘描述’不能自己给出，只能是被人给出。
即：the description given by people = people gave the description.
因为此处用的是‘被动语态’，所以用 given . 祝你天天快乐。

the description were extraordinrily similar. 这是主句，given by people 过去分词短语作定语修饰description，who claimed to have seen the puma这是定语从句修饰people。
given by people是一个被动语态。